1. Field of the Invention
Exemplary embodiments of the invention relate to a lens, a backlight assembly and a display apparatus having the lens. More particularly, exemplary embodiments of the invention relate to a lens, a backlight assembly and a display apparatus having the lens, with respect to fewer light sources.
2. Description of the Related Art
A liquid crystal display (“LCD”) apparatus needs an external light source for displaying an image with desirable brightness since the LCD apparatus cannot generate light by itself. The LCD apparatus includes a backlight assembly as the external light source, and a LCD display panel which displays the image using light from the external light source.
The backlight assembly includes a light source which may be mounted on a printed circuit board (“PCB”) substrate, and may be classified into an edge type assembly and a direct type assembly according to the position of the light source. In the edge type assembly, the light source is disposed at the edge of the LCD display panel, such that the light generated by the light source passes through a light guide plate, which is disposed under the LCD display panel, and is provided into the LCD display panel. In the direct type assembly, a plurality of light sources is disposed under the LCD display panel and the light generated by the light sources is provided directly into the LCD display panel. The direct type assembly might have higher brightness and better contrast ratio than the edge type assembly.
A cold cathode fluorescent lamp (“CCFL”) may be used for the light source of the direct type assembly. As a light source, a light emitting diode (“LED”) lamp may be used owing to advantages of a long life-time, lower power consumption, a light weight and a smaller thickness.
The LED lamp includes a point light source and a plurality of LED packages generating light. The LED package distributes light generated and emitted by the point light source. The point light from the point light source is changed into a planar light or surface light by a lens.
However, the point light source of the LED lamp has a small light distribution area for each point light source and a limited brightness. Thus, the backlight assembly may include hundreds of point light sources and/or LED lamps. As the number of the point light sources and/or LED lamps is increased, the number of the PCB and/or a size of the PCB is increased. Thus, the manufacturing cost of the LCD display apparatus is greatly increased.